AU2017282723A1 - Vehicular delivery of a substance to an area of land - Google Patents

Abstract

A method of treating an area of land. A vehicle delivers a first substance. The vehicle automatically switches from delivering the first substance to delivering a second substance, based on at least one parameter of present or predicted weather conditions.

Description

VEHICULAR DELIVERY OF A SUBSTANCE TO AN AREA OF LAND

FIELD

This invention relates to the vehicular delivery of a substance to an area of land such as an agricultural area.

The invention will be described by reference to various examples. The invention is not limited to these examples.

BACKGROUND

Modern agriculture entails the delivery of a wide variety of substances such as seeds, fertilisers and pesticides to the agricultural area. Spraying is one popular mode of delivery.

Sometimes the substances are delivered to other than their intended location. In the context of spraying, such misplacement is known as overspray or drift.

Such misplacement is of economic significance. At the very least, the misplaced substance is typically wasted, and the consequences can be far more serious - for example, the misplacement of a non-selective herbicide could destroy a crop adjacent the agricultural area.

Various rules apply to the delivery of substances to agricultural areas with the intent of avoiding problematic substance-misplacement. Nonetheless, substance-misplacement remains a significant problem.

It is often desirable to minimise the amount of substance delivered, at least to reduce the cost of the supplied substance. Moreover, the overuse of pesticides is correlated with the emergence of pesticide-resistant pests.

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The misplacement of substance and the amount of substance required to treat a given agricultural area can be minimised by careful manual application of the substance, e.g. by individually hand-spraying weeds. This is of course not economic in many agricultural contexts, such as in the context of broadacre crops. Accordingly, the vehicular delivery of substances, such as the application of pesticides by vehicles in the form of tractortowed (or mounted) spray rigs, remains the standard practice.

The invention aims to provide improvements in and for the delivery of a substance to an area of land, or at least to provide an alternative for those concerned with so delivering.

SUMMARY

Substance delivery vehicles are typically accompanied by a human operator; for example, a towed spray rig is typically accompanied by a human operator in the cab of the tow vehicle. The present inventors have recognised that:

a) substance-misplacement is often the result of error by the accompanying human (e.g. the result of a human in charge of a spray rig failing to follow the rules); and

b) automatically controlling the delivery of the substance minimises the prospects of such errors (amongst other advantages).

Various methods of, and apparatus for, treating areas of land are disclosed.

One aspect of the invention provides a method, of treating an area of land, including a vehicle delivering a first substance; and the vehicle automatically switching, from delivering the first substance to delivering a second substance, based on at least one parameter of present or predicted weather conditions.

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The switching may be based on parameter(s) such as wind speed, wind direction, a relationship between the wind direction and a direction to a feature, proximity to a or the feature, air temperature, humidity, and/or a likelihood of rain within a threshold time period.

The first substance may be a non-selective herbicide and the other substance may be a selective herbicide.

The area of land may be positioned relative to an area at risk of receiving misplaced substance, in which case the second substance may be less harmful, than the first substance, to the area at risk

The vehicle may be an autonomous vehicle.

Another aspect of the invention provides a vehicle, for treating an area of land, including one or more delivery mechanisms for delivering a first substance and a second substance; and a control arrangement to control the delivery mechanism(s);

the control arrangement being configured to automatically switch, from delivering the first substance to delivering a second substance, based on at least one parameter of present or predicted weather conditions.

The vehicle may include a weather sensor.

The control arrangement may be an onboard control arrangement.

Another aspect of the invention provides an unmanned vehicle, for delivering one or more substances to an agricultural area, including a control arrangement automatically responsive to an indication of future weather.

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The control arrangement may be configured to alter a path of the vehicle based on the indication of future weather.

Preferably, the vehicle is configured to prioritize sensitive portions of the area in response to an indication of deteriorating weather. The alteration may be to minimize the risk of the vehicle bogging.

The vehicle may be configured to cease or modify the delivery substance(s) in response to an indication that it will rain and/or an indication that the wind will shift.

Another aspect of the invention provides a method including a vehicle delivering a substance to an agricultural area; and automatically controlling the delivery of the substance.

Another aspect of the invention provides the vehicle.

Another aspect of the invention provides an automated controller for controlling the delivery of the substance.

Another aspect of the invention provides a vehicle system including a vehicle for delivering a substance to an agricultural area; and an automated controller for controlling the delivery of the substance.

The vehicle is preferably a land vehicle, and is most preferably self-propelled.

Alternatively, it may be an aerial vehicle such as a multi-rotor drone. In some variants of the method, the vehicle is configured to automatically follow a predefined path.

Preferably, the vehicle is an autonomous vehicle.

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PCT/AU2017/050589 “Autonomous vehicle” and variants of this term are used herein to refer to a vehicle capable of sensing, and adjusting its motion in response to, its surroundings so that it may operate without human intervention. The term does not take in a GPS-guided tractor that automatically follows a predefined path but requires a human operator to deal with anything that might have changed along that path. According to preferred forms of the method, the vehicle is not accompanied by a human. Other forms of the method may entail an automated substance delivery device, e.g. a spray rig, towed by a tractor with a human operator at the wheel.

According to some variants of the method the automatically controlling is based on an indication of the weather.

The automatically controlling may be discontinuing the delivery. The method may include discontinuing delivery if the air temperature exceeds a threshold such as 28°C. The method may include discontinuing delivery if the humidity exceeds a threshold such as a At of 2°C. Herein At refers to the difference between wet bulb and dry bulb temperatures. The method may include discontinuing delivery if the humidity falls below a threshold such as a At of 8°C. The method may include discontinuing delivery if the wind speed exceeds a threshold such as 15km/hr. The method may include discontinuing delivery if the wind speed falls below a threshold such as 3 km/hr.

Preferably the vehicle includes a processing arrangement configured to apply logic (such as the logic set out in the preceding paragraph) to automatically control the delivery of the substance based on the indication of the weather. Alternatively, the vehicle may simply respond to control signals from an automated remote controller external to the vehicle and configured to apply the logic.

The method may include a sensor of the vehicle sensing to provide the indication of the weather; e.g. the vehicle may have onboard temperature, wind and/or humidity sensors.

Alternatively, the vehicle may have a data inlet, e.g. an aerial, for receiving the indication. The indication could be received from one or more sensors mounted on or in

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PCT/AU2017/050589 proximity to the area to be treated. Alternatively, it may be received from a remote source, e.g. via the internet.

A rate at which the substance is delivered may be controlled based on a speed of the vehicle - for example, to deliver a controlled (e.g. fixed) amount of substance per square metre.

The delivery of substance may be spraying. In the context of broadacre crops, the substance and a suitable carrier such as water may be sprayed as atomised droplets from downwardly-directed nozzles. Alternatively, a spray rig may deliver substance to the area laterally or even upwardly to treat features of the area such as grape vines and almond trees. Other possible modes of delivery include spreading granules and applying gels or liquids (e.g. with the aid of a wick wiper).

The substance is preferably a pesticide. As such the method may be a method of controlling one or more pests. The control could be proactive or reactive control.

The substance may be a herbicide. As such the method may be a method of controlling plants. Preferably the herbicide is glyphosate, glyphosinate, paraquat, diquat, a phenoxy herbicide (such as 2,4D amine), a pyridine herbicide (such as picloram, fluroxpyr, triclopyr or aminopyralid), a triazine herbicide (such as ametryn, atrazine or simazine) or metsulfuron.

The herbicide may be a pre-plant herbicide - a non-selective herbicide applied to soil before planting. Alternatively, the herbicide may be a pre-emergence herbicide applied before the weed seedlings emerge through the soil surface. Alternatively, the herbicide may be a post-emergence herbicide applied after weed seedlings have emerged through the soil surface.

The herbicide may be soil applied. Soil applied herbicides are usually taken up by the root or shoot of the emerging seedlings and used as pre-plant or pre-emergence treatment. Alternatively, the herbicide may be foliar applied.

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The substance may be an algicide. As such the method may be a method of controlling algae.

The substance may be an avicide. As such the method may be a method of controlling birds.

The substance may be a bactericide. As such the method may be a method of controlling bacteria.

The substance may be a fungicide. As such the method may be a method of controlling fungi. The fungicide may be a translaminar fungicide which redistributes itself from the upper, sprayed leaf surface to the lower, unsprayed surface. Preferably the fungicide is inorganic (such as sulfur- or copper-based), dithiocarbamate, ethyl phosphonate, methyl acrylate, oximino acetate, methoxy carbamate or triazole.

The substance may be an insecticide. As such the method may be a method of controlling insects. The insecticide may be a natural insecticide, such as nicotine, pyrethrum and neem extracts, made by plants as defenses against insects. Alternatively, the insecticide may be an inorganic insecticide, i.e. one or more metals. Alternatively, the insecticide may be an organic insecticide. Preferably the insecticide is carbamate, organophosphate, phenypyrazole, pyrethroid, neonicotinoid, spinosyn, avermectin, bacillus thuringiensis, buprofezin or diafenthiuron.

The substance may be an acaricide. As such the method may be a method of controlling arachnids such as mites.

The substance may be a molluscicide. As such the method may be a method of controlling molluscs such as snails. Preferably the molluscicide is metaldehyde, ferric sodium EDTA, iron phosphate, methiocarb or thiodicarb.

The substance may be a rodenticide. As such the method may be a method of controlling rodents.

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The substance may be a virucide. As such the method may be a method of controlling one or more viruses.

The pesticide may be either selective or non-selective. By way of example, selective herbicides control unwanted plants without doing unacceptable harm to any wanted plants intermingled with those unwanted plants. Aryloxyphenoxypropionates (‘Fops’), such as fluazifop (Fusilade), and cyclohexanediones (‘Dims’), such as sethoxydim (Sertin), are examples of selective grass herbicides.

It is possible that pesticides may be mixed and/or that some pesticides have a dual action. As such, a single set of actions may be, for example, both a method of controlling one or more plants and a method of controlling one or more insects.

The pesticide may be a contact pesticide. Contact pesticides, in contrast to systemic pesticides, act via direct contact with the pest or part thereof. Contact herbicides kill the parts of the target plant(s) with which they come into contact. Contact insecticides act via direct contact with target insect(s).

Alternatively, the pesticide may be a systemic pesticide. Systemic pesticides, in contrast to contact pesticides, are absorbed and systematically distributed within plants.

Systemic herbicides are absorbed by and transported internally within unwanted plant(s), typically via their stems and/or leaves. Systemic insecticides are absorbed and transported internally within wanted plants to act on target insect(s) which ingest the wanted plant(s).

According to some variants of the method the automatically controlling is based on the vehicle’s location relative to a pre-defined feature, e.g. based on whether or not the vehicle is within a pre-defined exclusion zone.

The controlling may be based on a distance of the vehicle from the feature and/or a direction of the vehicle from the feature. The direction may be related to the direction of the wind. The delivery may be stopped based on the vehicle being upwind of a feature,

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e.g. stopped in response to the vehicle being a) upwind of the feature, and b) within a distance of the feature. The distance may be based on a wind speed and/or other parameters. The controlling may be based on one or more parameters characterising the feature, e.g. when spraying a non-selective herbicide, an exclusion zone may be defined about any crop and a larger exclusion zone about a) a sensitive crop, b) a crop within a “withholding-period” prior to harvest, or b) a certified organic crop.

In the context of spraying phenoxy herbicides (2,4D), cotton, grapes and tomatoes are sensitive crops. Often it is also appropriate to define an exclusion zone about locations frequented by humans, e.g. about houses and public areas such as roads, particularly when spraying insecticides which tend to be more toxic to humans than herbicides or fungicides.

According to some variants of the method the automatically controlling is based on an indication of a pest.

The method may include a sensor of the vehicle sensing to provide the indication of the pest. For example, the vehicle may have onboard photo-detectors for detecting broadleaf weeds. Spray and detection arrangements such as those marketed under the trade mark Weed-lt™ may be employed. Alternatively, the vehicle may have an or the data inlet, e.g. an or the aerial, for receiving the indication of the pest. The indication could be received from one or more sensors mounted on or in proximity to the area to be treated. Alternatively, it may be received from a remote source, e.g. via the internet.

The combination of a) spray and detection arrangements such as those marketed under the trade mark Weed-lt™, and b) autonomous operation, has been found to be particularly advantageous. Such arrangements are conventionally moved by a humandriven tractor. With an accompanying human operator, economics dictates a wide boom (e.g. 36m) and a certain speed. Human-operated substance-delivery vehicles are typically operated at a maximum speed limited by:

a) the abilities of the vehicle;

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b) an estimate of the risk of damage to the vehicle and/or substance delivery devices caused by speeding over rough ground; and

c) an estimate of the ability to uniformly deliver substance limited by:

i. the substance delivery device bouncing over rough ground, and ii. the driver’s ability to avoid overlap and missing any ground.

Various of the exemplified substances may be mixed to form a mixture. That mixture may be the substance delivered in accordance with the described method. By way of example, a mixture of paraquat and diquat is an advantageous herbicide.

Speed and width both detract from the performance of the arrangement. With such booms, undulations in the ground can mean that portions of the boom are metres from the ground. In contrast, an autonomous vehicle is not paid by the hour and can be economically operated at a lower speed and with a narrower boom (e.g. 8m). For example, the autonomous vehicle may be operated substantially continuously day and night to slowly and accurately deliver substance to where it is needed, e.g. to deliver herbicide to individual weeds.

The disclosed methods of treatment may entail automatically co-ordinating the delivery of two or more substances. This may entail the delivery of each of the substances being automatically controlled. The automatic co-ordination may be switching from one substance to another. By way of example, a vehicle may carry a first substance delivery mechanism including a storage vessel and spray nozzles and a second substance delivery system also including a tank and spray nozzles. Such a vehicle could be advantageously used to cost-efficiently deliver a pesticide in variable weather conditions. By way of example, whilst the wind remains below a threshold, one of the delivery systems might be activated to deliver a low-cost, broad-spectrum, non-selective herbicide. The controller may be configured to respond to the wind rising above a threshold to deactivate this first delivery system and (so long as the wind remains below

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PCT/AU2017/050589 a second, higher, threshold) activate the second substance delivery system to deliver a more expensive selective herbicide. As such the treatment of the area (in this case herbicide treatment) can continue even when the weather does not permit the use of the lower cost substance and at the same time the expense of spraying the entire area with the higher cost substance is avoided. In another example, 2,4D may be sprayed across the bulk of an area and a more expensive product sprayed across areas adjacent sensitive areas.

In some examples, the automatically controlling delivery is simply continuing or discontinuing. In other examples, the rate at which substance is delivered may be varied. The rate may be measured in various terms, such as a volume of substance and carrier substance per unit of time. In yet other examples, the delivery of substance is controlled by varying the motion of the vehicle. The delivery of the substance may be controlled by varying the path of the vehicle. By way of example, the vehicle may be configured to spray certain portions of the agricultural area (such as portions adjacent sensitive areas) whilst the wind remains below a certain threshold, and then move on and continue spraying in other areas if the wind picks up.

In yet other examples, the controlling delivery may entail controlling a droplet size. This could be implemented using proprietary equipment sold under the trade mark Case AIM Command™. Alternatively, it may be implemented by switching to a second spray line equipped with different nozzles.

The indication of the weather may be an indication of the substantially current weather. Alternatively, it may be an indication of some aspect of future weather, such as a weather forecast. By way of example, the vehicle may be configured not to spray if rain is expected. The logic could be as simple as “do not spray if rain is expected within a defined period, e.g. within two hours”. Alternatively, more complex logical functions, such as those that take account of the volume of expected rain, are possible.

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A weather forecast may inform the path planning. By way of example, the vehicle may be configured to automatically adjust its course to deliver substance to the more sensitive areas of the agricultural area (e.g. those adjacent sensitive areas such as a neighbour’s crop) whilst conditions are suitable for those areas and in preference to other, more robust portions of the agricultural area. Path planning may be adjusted to deliver substance to any areas that will become exclusion zones after a predicted wind change.

Variants of the disclosed methods and apparatus may be applied to the treatment of areas of land other than agricultural areas. In particular some variants may be applied in the context of railway and/or power line abutments, e.g. for weed control in these areas. Likewise some variants may be similarly applied in the context of remote airstrips. Indeed whilst some variants of the invention might be applied to agricultural and nonagricultural areas having growing plants, other variants may be advantageously applied in other contexts, e.g. applied in the context of surface treatments to concreted areas.

BRIEF DESCRIPTION OF DRAWINGS

An embodiment of the apparatus will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a front perspective view of an autonomous vehicle;

Figure 2 is a rear perspective view of the autonomous vehicle of Figure 1; and

Figure 3 is a front perspective view of another autonomous vehicle.

DESCRIPTION OF EMBODIMENTS

The vehicle 1 is a 4x4 land vehicle including a respective hydraulic motor for each of its four wheels. The forward half of the vehicle is articulated relative to the rear half to enable the vehicle to turn.

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An 8m wide boom 3 is carried at the rear of the vehicle 1. Photo-detector I spray units 5 are mounted along the boom to detect weeds and spray the weeds with a suitable herbicide. The vehicle 1 carries photo-detector / spray units sold under the trade mark Weed-lt™. The vehicle 1' carries photo-detector / spray units sold under the trade mark Weed Seeker™. The vehicle 1 also carries a substance store which in this example takes the form of a tank 7 carried by a rear half of the vehicle.

The photo-detector I spray units 5 are but one example of a possible pest sensor. Reflectance sensors can be calibrated to identify specific insects and diseases. Nonoptical pest sensors are also contemplated.

An onboard controller 9 controls both motion of the vehicle and the deliverance of the herbicide via the units 5. The controller 9 is supplied with information from antennae 11. The antennae 11 include GPS antennae to assist with navigation. The vehicle further includes obstacle sensors 13, 15 to enable it to sense and adjust its motion in response to its surroundings so that it may operate without human intervention. As such the vehicle 1 is an autonomous vehicle. The vehicle 1 has no seat, cabin, operator platform or other facility for an onboard operator.

In this case the obstacle sensors 13, 15 include cameras 13 and touch sensors 15. These obstacle sensors allow the vehicle to detect obstacles (such as fallen trees) along the vehicles’ path. One or more LIDAR sensors may be used to detect obstacles (in addition or as an alternative to the obstacle sensors 13, 15).

Such means of obstacle detection are employed so that the vehicle does not simply crash into the obstacle but rather appropriate adjustments to the vehicle’s motion can be made. The adjustment could simply be stopping. This would allow the vehicle to be operated in an agricultural area (where new obstacles can and do appear from time to time) without an accompanying human. More preferably, the adjustment is so as to allow the vehicle to continue operation, e.g. the controller may plot a new course around the

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PCT/AU2017/050589 obstacle. Persons of skill in the art will appreciate that there may be a variety of satisfactory approaches to obstacle avoidance.

The controller 9 is configured to receive, via antennae 11, indications of the current (or substantially current) weather from local weather stations about the agricultural area. These indications include indications of air temperature (°C), humidity (At, °C) and wind speed (km/h). Other examples of the vehicle may be equipped with an onboard weather station to provide the indication(s).

The controller 9 applies logic to these indications to control the delivery of substance based on the indications. In this example, the controller 9 deactivates the photodetector I spray units 5 if any one of the following shut-down criteria is satisfied:

• the air temperature is above 28°C;

• the At is outside of the range 2°C to 8°C;

• the wind speed is outside of the range 3 km/h to 15 km/h.

The 15 km/h limit is to limit the distance that the substance might be carried by strong wind. Spraying in hot, dry conditions can also lead to overspray. Such conditions dry the sprayed droplets, leaving smaller droplets, or even dry active ingredient, more susceptible to carriage by the wind. Spraying in low wind conditions (including zero wind) can also lead to overspray. Such conditions can result in ‘inversion’ which entails warm air rising from the ground. The rising air can take any spray with it, resulting in a cloud of spray which may be delivered to ground some distance from the agricultural area. Similar criteria may be applied to automatically switching between substances.

Advantageously, the controller may also halt the vehicle when one of the shut-down criteria is satisfied, then restart both the vehicle and the spraying at the next point in time that no shut-down criteria are satisfied. As such, the vehicle may be operated in marginal weather conditions and sufficiently avoid overspray by stop-starting. This may

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PCT/AU2017/050589 allow a field to be sprayed days earlier than waiting for more satisfactory weather in line with conventional practice. This avoidance of delay can be valuable; e.g. many pests infest crops at exponential rates such that early treatment requires less pesticide and is more effective.

The controller 9 also controls the delivery of substance based on the position of the vehicle. According to this preferred form of the method, the controller 9 prevents delivery of substance when the vehicle is too close to any sensitive area.

The various types of sensitive area and sensitivity can depend on the substance being delivered. When spraying with non-selective herbicides, all crops, pasture and home gardens are susceptible. When spraying with any pesticides, neighbouring crops which are less than the “withholding period” until harvest for that particular pesticide risk being rendered unsaleable by overspray. Pesticide drift onto any certified organic farms will cancel the organic status for any area drifted onto. As a generality, insecticides are more toxic to people than herbicides or fungicides, so houses and public areas like roads are a concern.

Sensitive areas also include crops or bush where commercial bees are foraging. Pesticides drift onto aquatic areas such as rivers, natural and man-made water courses, swamps and lakes, etc, is of major environmental concern.

Common agricultural substances, such as glyphosate (Roundup™), phenoxy herbicides and paraquat, may be applied in accordance with the disclosed method. Glyphosates (Roundup™) is the most widely used pesticide followed by phenoxy herbicides and paraquat, mainly because they are the cheapest non-selective herbicides (used in zero tillage).

Some substances are particularly problematic when misplaced. Phenoxy herbicides (2,4D) and endosulfan are examples of such “particularly problematic substances”.

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Phenoxy herbicide (2,4D) is a selective, systemic, foliar absorbed post-emergence herbicide. It causes major yield loss to crops such as cotton, grapes and tomatoes at extremely low concentrations. The most volatile formulations have been banned in most areas, however there are still large losses due to the more stable formulations.

Endosulfan is an insecticide which has been virtually banned, partially due to residue in beef from cattle eating pasture that endosulfan had drifted onto.

Currently, pesticide regulators legislate large buffer zones around certain sensitive areas when delivering certain particularly problematic substances. Preferred forms of the disclosed method reduce the risk of unacceptable substance-misplacement and are therefore particularly advantageous when they entail the delivery of such particularly problematic substances. In view of this risk reduction, regulators may well reduce the buffer zones. This would release more land for profitable food production.

Delivering substance in accordance with preferred forms of the disclosed method makes efficient use of the substance and thus reduces the significance of the cost of the substance. In turn, it becomes more economic to use more expensive pesticides, e.g. to better manage resistance. Glyphosinate, pyridine group chemicals, and diquat are examples of such pesticides.

Various forms of the invention may entail one or more of the following herbicides:

• Aminopyralid is a broadleaf herbicide in the pyridine group, used to control weeds on grassland, such as docks, thistles and nettles.

• Atrazine, a triazine herbicide, is used in com and sorghum for control of broadleaf weeds and grasses.

• Clopyralid is a broadleaf herbicide in the pyridine group, used mainly in turf, rangeland, and for control of noxious thistles.

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PCT/AU2017/050589 • Dicamba is a post-emergent broadleaf herbicide with some soil activity.

• Glufosinate ammonium, a broad-spectrum contact herbicide, is used to control weeds in vineyards and orchards or after the crop emerges in selected crops or for total vegetation control on land - not used for cultivation or where there is no emerged crop.

• Fluazifop (Fusilade Forte™) is a post-emergence, foliar absorbed, translocated grass-selective herbicide with little residual action.

• Fluroxypyr, a systemic, selective herbicide, is used for the control of broadleaf weeds in small grain cereals, maize, pastures, rangeland and turf.

• Imazapyr, a non-selective herbicide, is suitable for the control of a broad range of weeds, including terrestrial annual and perennial grasses and broadleaf herbs, woody species, and riparian and emergent aquatic species.

• Imazapicis a selective herbicide for both the pre- and post-emergent control of some annual and perennial grasses and some broadleaf weeds.

• Imazamox, an imidazolinone manufactured by BASF™ for post-emergence application, is an acetolactate synthase (ALS) inhibitor (sold under trade names Raptor™, Beyond™, and Clearcast™).

• Linuron is a non-selective herbicide for controlling grasses and broadleaf weeds.

• MCPA (2-methyl-4-chlorophenoxyacetic acid) is a phenoxy herbicide selective for broadleaf plants and widely used in cereals and pasture.

• Metolachlor is a pre-emergent herbicide for controlling annual grasses in com and sorghum.

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PCT/AU2017/050589 • Pendimethalin is a pre-emergent herbicide, for controlling annual grasses and some broadleaf weeds in a wide range of crops, including com, soybeans, wheat, cotton, many tree and vine crops, and many turfgrass species.

• Picloram, a pyridine herbicide, mainly is for controlling unwanted trees in pastures and edges of fields. It is a synthetic auxin.

• Sodium chlorate a non-selective herbicide.

• Triclopyr, a systemic, foliar herbicide in the pyridine group, is used to control broadleaf weeds while leaving grasses and conifers unaffected.

• Several sulfonylureas, including Flazasulfuron and Metsulfuron-methyl, act as ALS inhibitors and in some cases are taken up from the soil via the roots.

Various forms of the invention may entail one or more of the following organic herbicides:

• Com gluten meal (CGM) is a natural pre-emergence weed control.

• Vinegar is effective for 5-20% solutions of acetic acid.

• D-limonene (citrus oil) is a natural degreasing agent that strips the waxy skin or cuticle from weeds, causing dehydration and ultimately death.

• Saltwater or salt applied in appropriate strengths to the root zone will kill most plants.

• Monocerin produced by certain fungi will kill certain weeds such as Johnson grass.

Various forms of the invention may entail one or more of the following insecticides:

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PCT/AU2017/050589 • Organochloride such as Endosulfan.

• Organophosphate such as Acephate, Azinphos-methyl, Bensulide, Chlorethoxyfos, Chlorpyrifos, Chlorpyriphos-methyl, Diazinon, Dichlorvos (DDVP), Dicrotophos, Dimethoate, Disulfoton, Ethoprop, Fenamiphos, Fenitrothion, Fenthion, Fosthiazate, Malathion, Methamidophos, Methidathion, Mevinphos, Monocrotophos, Naled, Omethoate, Oxydemeton-methyl, Parathion, Parathion-methyl, Phorate, Phosalone, Phosmet, Phostebupirim, Phoxim, Pirimiphos-methyl, Profenofos, Terbufos, Tetrachlorvinphos, Tributes or Trichlorfon.

• Carbamate such as Aldicarb, Bendiocarb, Carbofuran, Carbaryl, Dioxacarb, Fenobucarb, Fenoxycarb, Isoprocarb, Methomyl or 2-(1-Methylpropyl)phenyl methylcarbamate.

• Pyrethroid such as Allethrin, Bifenthrin, Cyhalothrin, Cypermethrin, Cyfluthrin, Deltamethrin, Etofenprox, Fenvalerate, Lambda-cyhalothrin, Permethrin, Phenothrin, Prallethrin, Resmethrin, Tetramethrin, Tralomethrin or Transfluthrin.

• Neonicotinoid such as Acetamiprid, Clothianidin, Imidacloprid, Nithiazine, Thiacloprid orThiamethoxam.

• Ryanoid such as Chlorantraniliprole, Cyantraniliprole or Flubendiamide.

• Insect growth regulator such as Benzoylureas, Diflubenzuron, Flufenoxuron, Cyromazine, Methoprene, Hydroprene or Tebufenozide.

• Plant-derived insecticide such as Anabasine, Anethole, Annonin, Asimina, Azadirachtin, Caffeine, Carapa, Cinnamaldehyde, Cinnamon leaf oil, Cinnamyl acetate, Citral, Deguelin, Derris (rotenone), Desmodium caudatum, Eugenol, Linalool, Myristicin, Neem (azadirachtin), Nicotiana rustica (nicotine), Peganum

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PCT/AU2017/050589 harmala, Oregano oil, Polyketide, Pyrethrum, Quassia, Ryanodine, Tetranortriterpenoid or Thymol.

• Biological insecticide such as Bacillus sphaericus, Bacillus thuringiensis, Bacillus thuringiensis aizawi, Bacillus thuringiensis israelensis, Bacillus thuringiensis kurstaki, Bacillus thuringiensis tenebrionis, Nuclear Polyhedrosis virus, Granulovirus, Spinosad (Spinosyn A), Spinosyn D or Lecanicillium lecanii.

• Diatomaceous earth, Borate, Borax or Boric Acid.

Preferred forms ofthe invention make decisions based on information about the area surrounding the area to be treated, e.g. information such as • crops that are potentially sensitive, or at a sensitive stage of growth, to the range of treatments available to the target area;

• organic certified areas - only drift of organic certified products allowed;

• crops that are within the harvest withholding period for the range of treatments available to the target area;

• public areas e.g. roads, houses;

• timing of school bus route; and • livestock and grazing areas.

On board decisions are made to determine what parts of the field are safe to treat with the range of products available to do the required treatment with the prevailing weather conditions. This will include buffer zones where with a certain weather condition and the wind blowing towards a sensitive crop the treatment can continue to within a determined distance.

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A weather station on board and/or other weather stations around the field to be treated provide real time weather data for the decision-making process.

When weather data is used to assess the risk to neighboring areas and/or the likelihood of the treatment being successful. If the risk and/or likelihood is/are unsatisfactory the vehicle will stop the application. The vehicle may then locate to a different area of the field if the treatment can continue safely there or, if available, change to a different treatment. If neither of these options are available, the treatment may halt until suitable conditions return.

Example - For cost and efficacy of weed control a phenoxy herbicide (e.g. 2,4-D) on a fallow field has been selected (Option 1). There is a susceptible cotton crop 3km away.

The vehicle uses the weather data to determine if it is safe to spray with option 1 herbicide. If the wind direction is blowing away from the cotton crop then spraying will proceed while Delta T (humidity), temperature and wind speed are within limits. Should the wind direction be variable and coming within a threshold (e.g. 20 degrees) of the direction of the cotton crop the vehicle may continue spraying with option 1 but only if the other parameters have been changed to Delta T is say 2 degrees lower, temperature 4 degrees lower and wind speed 5 km/hr slower. As such the humidity, temperature and wind speed thresholds vary as a function of wind direction. If any one of the parameters is not met then spraying stops until weather conditions return to a suitable range or the farmer give the vehicle another “Option”.

Example - If the cotton crop is the neighboring field to the field being treated.

The vehicle will determine a safe buffer zone between where it can spray with “Option 1” and the cotton field. Firstly the wind needs to be blowing away from the cotton and then the width of the buffer zone will be determined by the consistency and speed of the wind together with the Delta T and temperature. As such the criteria is based on proximity and direction to a feature (the cotton) and also based on the weather. For the buffer zone and parts of the field where wind direction will take drift to the cotton an alternative

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PCT/AU2017/050589 option (Option 2) is loaded on the vehicle. Option 2 could be Roundup Ready Herbicide (Monsanto trade mark) where the cotton crop is a glyphosate tolerant variety. The vehicle would switch to spraying Roundup Ready Herbicide in areas of the field that it had determined Option 1 is an unacceptable risk to spray.

The vehicle receives weather forecast information that it then uses to determine what limitations or opportunities the change in weather conditions will have on the treatment of a field.

• A forecast wind change may require a treatment to be stopped in all or parts of a field or it may allow a treatment to start where it currently is not safe to do so.

• The forecast for rain may trigger a label direction to cease treatment for a nominated time frame prior to rain. This could be due to the pesticide washing of the target plant and not doing the job intended or it could be that by washing off it will be an environmental contaminate.

• Forecast temperature and humidity conditions may dictate that there will only be a short window of suitable spraying condition causing the vehicle to prioritise areas that are the most critical. A different treatment with a wider range of temperature and humidity parameters may be used for the remainder or simply take more days to complete the treatment.

Example - For cost and efficacy of weed control Glyphosate CT (Nufarm brand) has been chosen by a farmer to be applied by a vehicle on a field. The neighboring field has a wheat crop growing which is sensitive to Glyphosate.

The vehicle accesses local weather forecast data and on board weather station data to determine that currently the wind is blowing away from the wheat field but in 2 hours the wind direction is predicted to change and blow towards the wheat field. Using this information the vehicle would start spraying the area of the field closest to the wheat

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PCT/AU2017/050589 field to create a large buffer zone for when the wind change would make spraying beside the wheat field more dangerous.

Glyphosate should not be applied if rainfall is predicted within 6 hours. Knowing this the vehicle will cease spraying when the weather forecast predicts rain to fall in 6 hours.

Claims (24)

1. A method, of treating an area of land, including a vehicle delivering a first substance; and the vehicle automatically switching, from delivering the first substance to delivering a second substance, based on at least one parameter of present or predicted weather conditions.

2. The method of claim 1 wherein the switching is based on wind speed.

3. The method of claim 1 or 2 wherein the switching is based on wind direction.

4. The method of claim 3 wherein the switching is based on a relationship between the wind direction and a direction to a feature.

5. The method of any one of claims 1 to 4 wherein the switching is based on proximity to a or the feature.

6. The method of any one of claims 1 to 5 wherein the switching is based on air temperature.

7. The method of any one of claims 1 to 6 wherein the switching is based on humidity.

8. The method of any one of claims 1 to 7 wherein the switching is based a likelihood of rain within a threshold time period.

9. The method of any one of claims 1 to 8 wherein the first substance is a nonselective herbicide and the other substance is a selective herbicide.

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10. The method of any one of claims 1 to 9 wherein the area of land is positioned relative to an area at risk of receiving misplaced substance; and the second substance is less harmful, than the first substance, to the area at risk

11. The method of any one of claims 1 to 10 wherein the vehicle is an autonomous vehicle.

12. The method of any one of claims 1 to 11 wherein the area of land is an agricultural area.

13. A vehicle, for treating an area of land, including one or more delivery mechanisms for delivering a first substance and a second substance; and a control arrangement to control the delivery mechanism(s);

the control arrangement being configured to automatically switch, from delivering the first substance to delivering a second substance, based on at least one parameter of present or predicted weather conditions.

14. The vehicle of claim 13 wherein the switching is based on wind speed.

15. The vehicle of claim 13 or 14 wherein the switching is based on wind direction.

16. The vehicle of claim 15 wherein the switching is based on a relationship between the wind direction and a direction to a feature.

17. The vehicle of any one of claims 13 to 16 wherein the switching is based on proximity to a or the feature.

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18. The vehicle of any one of claims 13 to 17 wherein the switching is based on air temperature.

19. The vehicle of any one of claims 13 to 18 wherein the switching is based on humidity.

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20. The vehicle of any one of claims 13 to 19 wherein the switching is based a likelihood of rain within a threshold time period.

21. The vehicle of any one of claims 13 to 20 including a weather sensor.

22. The vehicle of claim 13 to 21 wherein the control arrangement is an onboard control arrangement.

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23. The vehicle of any one of claims 13 to 22 being an autonomous vehicle.

24. The vehicle of any one of claims 13 to 23 wherein the area of land is an agricultural area.